Conventional magnetic storage systems comprise a thin film magnetic element with an inductive recording element mounted on a slider. The magnetic element is coupled to a rotary actuator magnet and a voice coil assembly by a suspension and an actuator arm positioned over a surface of a spinning magnetic disk. In operation, a lift force is generated by the aerodynamic interaction between the magnetic element and the spinning magnetic disk. The lift force is opposed by equal and opposite spring forces applied by the suspension such that a predetermined flying height is maintained over a full radial stroke of the rotary actuator assembly above the surface of the spinning magnetic disk.
An exemplary recording element comprises a thin film write element with a bottom pole P1 and a top pole P2. The pole P1 and pole P2 have a pole tip height dimension commonly referenced as “throat height”. In a finished write element, the throat height is measured between an air bearing surface (ABS) and a zero throat level where the pole tip of the write element transitions to a back region. The air-bearing surface is formed by lapping and polishing the pole tip. A pole tip region is defined as the region between the ABS and the zero throat level. The pole P1 and pole P2 each have a pole tip located in the pole tip region. The tip regions of the pole P1 and pole P2 are separated by a magnetic recording gap, which is a thin layer of insulation material.
The current trend in data storage systems strives for higher storage densities. Recording densities are increasing to meet the requirements to store large amounts of information. At higher recording densities (i.e., above 100 Gb/in2), perpendicular recording elements are utilized. Perpendicular recording elements can support higher recording densities because of a smaller demagnetization field in the recorded bits.
One typical perpendicular recording element utilizes three poles, P1, P2, and P3. Magnetic flux emanates from the pole P3 into the recording media and returns to the poles. Writing occurs at the pole P3. The recording resolution depends on the size and shape of the pole P3 rather than the gap length. In the perpendicular recording element, the gap between pole P1 and pole P3 is larger than allowed by longitudinal recording element designs, eliminating the need for a pole P1 pedestal.
As recording density increases, track distance decreases. For small track distances, a pole P3 may introduce adjacent track erasing if the pole P3 tip is shaped as a square. What is needed is a single pole element formed in a trapezoidal shape to eliminate the adjacent track erasing. In addition, the linear recording density can be further improved when a shield is added adjacent to the pole P3. The shielded perpendicular writer also provides a higher write-field gradient and reduced transition region in the recorded bits, improving linear density and reducing media noise.
The shielded perpendicular recording element presents distinct advantages for high-density recording. However, the fabrication of the shield and shield gap required by pole P3 may damage pole P3, or may create a shield gap at that is thinner at both edges of pole P3. Field leakage occurs through the thin gap region, resulting in reduced recording element efficiency.
What is therefore needed is a method for fabricating a shield and shield gap for the perpendicular recording element that maintains a uniform thickness of the shield gap without damaging the pole P3 during fabrication. The need for such a fabrication method and resulting write element has heretofore remained unsatisfied.